White colors in view port vs render output Eevee
To make emission lighting work properly in EEVEE, you need to use an Irradiance Volume (under &quot;Light Probes&quot; in add menu).

As you can see, without the volume, as soon as the emission object is out of camera view, the light from it disappears:

Scale the volume to encompass the area you want to boost the accuracy of the lighting (including emission values). You can adjust the detail from the properties panel.

Additionally, you need to bake the indirect lighting. Otherwise, although emission materials may glow (with bloom), they do not provide any lighting

Although I realize now I had some world lighting adding to the situation in the first image, you can still see that the lighting is more pronounced in this last photo. Also notice the lack of any light in my scene tree. All lighting is through emissions (except for a small amount of world lighting - that is a failure of my example, but does not change the effectiveness of the Irradiance Volume)

You can see the difference, as the room is now lit, even though the emission object is out of camera view: